The GBA SNES emulators are not great (no sound, fewer buttons, quite a few issues). If a game was ported to the GBA (either from SNES, PCE/TG16 or megadrive/genesis) it is a far better bet. NES emulation is not bad but the GBA resolution is lower than the NES and thus you have issues for some games.
" im not really into gba (if i want to i'll just buy some from ebay)"
Do you mean the hardware or the games? Because a lot of the good games command a decent price these days.
Not sure what you might have seen for 17 USD, probably some kind of 3 in 1. If you had a fully working DS lite I would suggest that but as you might not then I would have reservations.
If you want a shop a bit closer to home
http://www.shop01media.com/en/EZ-Flash is a former sponsor of here and is otherwise held in high regard. A bit pricier but closer if you want that sort of thing (they even price in NOK if you want).
Edit. Forgot the first question.
The 3 in 1 will function as a single game type thing but for the most part just runs off the back of a DS slot flash cart and uses the storage there for games and saves. No microSD unless you DS flash cart has it.
The EZ4 has those 5 models. All except the original GBA size one use microSD, the original GBA size one (which did see a new batch made in late 2013) use miniSD and I should note the adapters have caused no end of trouble for a lot of people. The EZTeam then made a new revision (I linked the first impressions thread) earlier this year which is full size GBA slot size (the others are smaller or a clone of the dust cover) but uses microSD instead. They also released a software update before then to allow all models to use SDHC type memory as well.
The main difference is the EZ4 lite deluxe (which is a copy of the DS lite dust cover) has slightly more onboard memory -- GBA games need fast memory to run (which is why some are limited and the supercard is not good as its memory is not good). In this case the deluxe has 256Mbit to the rest's 128Mbit (16 megabytes) of PSram which is used as RAM tends to be (written and data lost with the power) and 384 (48 megabytes) of NOR to the rest's 256 Mbit (32 megabytes). The trouble games list from earlier also has a list of all games greater than 128Mbit which is not that many at all really. NOR is slow to write and has some quirks (write files 1,2,3 and 4 and to remove 2 you will also have to remove 3 and 4) but it stays when you lose power.
Years ago there was some choice. Today it boils down to
Do you have a DS and just want some good GBA times?
If so consider a 3 in 1.
Do you have a GBA or want a more standalone affair?
In that case great, you get to find someone to sell you an EZ4.
Both are a tiny bit lacking compared to the height of the GBA era but they will both play basically all there is on the GBA and you will be hard pressed to do any better anyway.