A guy named Russell just wrote for advice on starting a T-Shirt biz. Here's my reply. I hope it helps!
Sounds like you have some great ideas and could really make a go of a t-shirt biz.
If I was starting as you are, perhaps I'd get into screen printing, setting up a shirt shop, and creating a focused marketing program, pushing Tshirt printing to a targeted group of markets in your area -- restaurants, schools, service businesses, retailers, government and university/college markets. Try google adwords and monthly postcard mailings to a list of 1000 or more. Network and hand out your card, talking up your biz, etc.
The inkjet transfer is a winning idea. Get one of those Epson printiers that can handle an 11 x 17 sheet.
Embroidery is a lucrative market. At first, it would be better to send the embroidery jobs out to a shop in your area, or maybe one that sells on the web. You can take a good markup, I've done a lot of outsourcing embroidery.
Maybe get a machine later as you add staff.
Good luck -- if you want to succeed, and are willing to put everything you have on the line, from smarts, guts, determination, ingenuity and capital, you will.