If you're going matrix you have two options, either a technomancer or a decker. The problem is that if you want to play a decker you need a good cyberdeck, and unless you can convince the others to help you steal one than with street level play it isn't an option.

Adept-decker is not a good idea, but not actually due to the essence problem (all you need is a datajack, it's suboptimal but still viable). There are no adept powers in the codebook that benefit a decker (I don't know about Street Grimoire), so being an adept is slightly pointless.

Also, bare in mind that Technomancers want high mental Attributes. It may be a good idea to go A attributes and B resonance, although the other way round should work.

Bare in mind that a lack of money is a lot less of an issue for magic-users and technomancers, due to their lack of need for expensive cyberwear.