Hi, I would love to do the same, i.e. print cards.
Can you guide me on: ...
Printer - if you've got one that can take 300gsm paper it'll do (sorry - don't know US/ Australian equivalent designation but towards the heavy end of inkjet papers) I've used Epson 1160, 1200, 2400 and 3880 over the last ten years or so
Layout - use Qimage to create a layout! - I'll attach one of mine. What you do is up to you!
Paper - you probably don't have these exact papers available (and you don't need them) but I mostly use
for a matt surface art paper I use a cotton fibre paper - for a smooth surface Innova IFA14 and for a textured surface Innove IFA12. These are both just over 300gsm.
for a textured gloss surface I use Permajet Fibre Base Royal 325 (325gsm). This is a gloss coated suface over cotton fibre paper. (I don't like mirror gloss smooth sufaces so don't have one for that)
These papers are simply the papers I usually have in stock for my fine art photography prints, and I just fold the A4 size to make a print. (Cheaper papers tend to crack on folding).
Folding - Find a local craft shop if possible and see what they have for folding cards (the tool I have is unnamed, and the small UK company I bought it from no longer exists) - there are lots of articles online on folding paper for cards too. Alternatively your usual paper supplier may also provide prefolded cards, though these may slightly catch the print heads on the fold, leaving a dirty smear.
Depending on volume, and intended use, the cheapest option could simply be finding a local printer and talking to them. (or you cold upload to redbubble and order cards from them!)