The walbro in tank replacement fits well with the appropriate fitting kit. not a hard job at all.
'runuts' had them for sale on here or at least he can tell you the right fitting kit, i bought mine off him.
Also watch out as there heaps of fakes on ebay ect so buy form a reputable source.
Read up on here under the fuel section on how to do it. heed their warning on the fuel line nut being tight. http://www.vfaq.com/index-main.html
What are you doing to tune for the bigger injectors? or you'll be extremely rich if you just throw them in.
i'm running late model evo 560cc injectors (evo 8 i think) on my vr4 motor.. straight fit..
but yes i'm running a bigger fuel pump and microtech..
these injectors go for cheap on evooz..