Ok.... here’s the deal.... I have a line on a yet another 717 motor.... in the pictures, it looks absolutely pristine condition... the guy knows nothing about it because his son is the one who purchased it.... I have one question... on the stator housing there are a few numbers stamped on it... am I correct to think that this is the production date?
It is 12/00....
It seems to me that you have a couple options here. None of these options are going to be "cost-effective", but it appears you might have already gotten the rough end of the stick.
Cheapest route / most work. Head over to Harbor Freight and purchase yourself a press. This is the only tool needed to rebuild your crank. HOWEVER, depending on the conditions the crank has seen through its life it might take a MIGHTY powerful press to break any cold welding. I know that I have had a similar situation where my 3-ton press was unable to do it and I had to take it to a machine shop where their 30-ton press was just about topped out before breaking the cold weld.
In addition to potentially requiring more force than you will be able to provide, this is not an easy job. For someone who has spent little to no time working on things like this, it is more than likely an undertaking that should be passed up. THAT IS unless you're looking to educate yourself through experience, in that case, you have nothing to lose (but time and money

).
More costly / Less work / quicker to get to the fun part. Pull the engine if it is not already, package the engine for shipping, contact one of the companies that sell rebuilt motors, ship them your core, wait for your new motor, drop it in the ski, and move on!
Here are a couple of places that you can get this service from.
http://www.rynopowersports.com
http://www.seadooengineshop.com/
*I cannot speak for the quality of work, turn around time, or any further details on these businesses as I have not personally used them. Perhaps someone else here can chime in*
Depending on the condition of the rest of the motor you could potentially just send in your crank and get a new one. In my opinion, you would be better off getting a whole new motor. the prices for a new motor and a new crank are not that far off from each other, so why not get the whole thing?
Words of advice:
Stay calm and stop freaking out. As with any motor vehicle land or water, you WILL encounter challenges and roadblocks. If your going to get anywhere with them you must take a few deep breaths, calm down, and think critically/analytically rather than emotionally.
Being bitten by the PWC bug is a pretty powerful thing, and it's hard not to just jump on the first thing you see. You must squelch this and maintain a realistic outlook on the potential any ski you're looking at has. Do not jump into anything uninformed! POST POST POST; people on here are very nice and willing to help you, use this to you ADVANTAGE! There is no need to become defensive the people on here are trying to help and they have experienced a lot of issues with these things and know what they are talking about. It may sound like they are being rough, but the reality of these skis are often very rough.
Remember that decades-old saying BOAT - bust out another thousand. WELL you now own a mini boat, you won't be needing to bust out thousands, but you will probably be busting out multiple hundreds. This is a reality you need to be prepared for and if it is out of your budget's range then maybe you should cut your losses.
I am sorry if this comes across harsh, but I am currently working on my first jet ski project - I initially dropped 400 and am now up to 1500 before the thing has even seen water. I too jumped into something before really knowing about it, but I don't regret this because now I know so much more about these things. This could be especially beneficial for someone who wants to flip PWCs. The more you know the more you can keep your head up for the next time around.
In a nut shell, you can approach this in two ways - As an inconvenience that is in your way to having fun.
Or as a learning experience that will not only teach you about PWC's and 2-strokes but will also be a valuable lesson in patients.