I need to replace the slide on the stock carb and I was looking on Ebay and was wondering if you guys could check this out and let me know if this would be a good replacement and if not where else could I find one. http://www.ebay.com/itm/151232466016

Also, I've been still trying to get the best jetting. I've ordered jets from MFG Supply and I have read that not all jets are equivalent or accurate as the oem jets. Do you guys think these jets are good enough?
http://www.mfgsupply.com/snowmobile/snowcarb/snowcarbjets/snowcarbpilotjets.html

Thanks for all your help. This has been a real struggle but Im keeping my patience with my mighty Zilla lol.

Use only genuine Mikuni or Keihin jets.  The few dollars you save by using the aftermarket jets will not offset the cost of doing a top end if you are unfortunate enough to get some jets that are not sized/dimensioned and marked correctly.

The hole size in a jet is only one of the many different dimensions that make a jet flow like it is supposed to flow.