If you have any intention of going bigger in the future then I would do the topfeed setup, I think the injectors are better. I've never really liked sidefeeds.
I have thought about it and there is no guarentee that it would fix the problem. Plus I don't have a spare car tog et me to work while the one injector is being cleaned.
Deatschwerks are excellent quality. Their side feeds will work just fine. Will the 850cc be enough for that 6262 though?
$450 injectors $150 TGV $25 fuel rails....I have a set I will get you on the cheap They are stock wrx fuel rails and I am pretty sure they would work fine you really need to up the pressure and volume. Now I have never used wrx fuel rails on a AVCS car, but provided you use topfeed tgv's it should work...maybe WJM can chime in. So now we are talking $625+tune and much better if you decide to go big down the road vs $550.
You forgot the labor...Although I am very handy and could probably do everything my self, I just don't have the time to risk having my car down for more than a day...sot hat would most likely mean I would have to pay someone to swap out TGV's, rails, injectors.