The MS can be a little intimidating, all you really need to do is surf http://www.msefi.com for a few days to understand how everything fits together, what you need to buy with the kit, if you need the flyback board that supports really low impedence injectors, etc...

Slick can order the parts, assemble, and test your board for you. Or you can do it yourself. Or, you can order the parts and the board and send it to someone else to assemble it - there are at least half a dozen places that I know of in my area (less than 50 miles) that will assemble PCB's. It depends on how much you want to spend.

http://www.rs-autosport.com/ also sells a lot of cool MS stuff. I bought a harness, a DB37 connector, and the 2 GM sensors from there. They also sell pre-assembled boards. If you decide to order the partial kit, order the rest of the components on your own, and assemble the thing on your own, it will cost somewhere between $150 and $200 for everything that you will need to get a MS doing fuel on a 2GNT.

Bottom line, I'd reccomend the MS. It's a LOT more powerful than the Portfueler, 034EFI, or big injectors + S-FMU + S-AFC. Seldom is the best option the cheapest, but this is the exception to the rule. A lot of people (including myself) have already or are jumping on the MS bandwagon - that means that there will be even more support out there for it. For a 2GNT with a turbo kit, the MS is an excellent option for meeting the fuel requirement.

EDIT: If you're lucky, you may be able to find someone that has a setup similar (like similar cams and similar injectors) to yours, and if you ask them nicely, they may give you their maps. The MS also has a nifty little feature that takes the 0-5 volt output signal from a wideband to tune the car at all times. No more open loop! You tell the MS what the target AFR is at X rpm and Y pounds of boost. Although I haven't played with it at all, I can imagine that it would do wonders to fine tune a car once you find a good base map.

2016 WRX STi Limited (current)
2001 A4 1.8tqms (donated)
1991 GVR4 #1933 (sold)
old.dsmregistry.com/detail.php?carid=218 (dismantled)