DONT worry much about the + in BLU+... most of the software that had the compatibility issue has already been 'fixed' in newer versions, all the good emulators are already working fine on BLU+, and new stuff getting released most is now including an option for BLU+ as well.
I would say don't buy from GBAX if you are in the US as the dollar is worthless over there now and you will pay a LOT more thru the exchange rate then if you bought from Lik Sang.
If lik sang is all sold out here is the website I ordered mine from, they do the same deal as lik sang (blu +, free game and RF module) for about the same price (well a little bit more at $190).
Anyways here is the link:
http://www.goldenshop.com.hk/AI-trad/aitrad.htm
and click on handheld console section on the left.
This place was very cool, responded to every email I sent them and got the GP to me fast after I ordered, in like 3 or 4 days now I forget. I recommend them 100% and would not hesitate to buy from them again. They are much less known than Lik Sang and should have GP's in stock. It will be BLU + but don't worry as I said... you wont be missing much