Mods with map sensor (87)
 

As above are there any mods I can get on with without doing the mass conversion?

I think maf conversion is one of the first things most will do. I guess you could do the exhaust but other than that I think you nned a maf swap, which isn't that difficult or expensive really.

Should i just go with a stock setup?

I think that's what most people do. Someone else with a little more experience should be able to give you a little more info on the swap as I've never actually done one, but going by what I've read in the past it's pretty easy and cheap if you pick up used parts.