I can advise on wide format dye sub. We have a 102" Mutoh 2628TD printing direct to fabric using Sensient Inks and heat set the ink using an AIT GFO-126 Rotary Heat Press. The one piece of advice I would tell you is that unless you have a business plan that can keep the machines running daily printing ALOT of dye sub, I would recommend subbing out the printing. We do all of our own sewing and finishing in house, but you could have that done as well. Locally in Atlanta, I can get dye sub printed and finished for $4.00 a square foot or just printed and cut off the roll for us to finish at $3.00/sq ft. We produce huge tradeshow exhibits so its not unusual for us to produce fabric graphics 8' High by 20+ feet wide for backwalls and structures. Our sewing table is 5'x25'. Of course you don't have to go into it on this scale, but you have to take into consideration the space you're going to need, the learning curve when dealing with fabric + the finishing (sewing), the costs of the equipment and even things like do you have enough electrical service coming into your space to power the heat press, oh and you have to vent the fumes coming off the heat press and the hood you use will help draw some of the heat out of the space. The press runs at 400 degrees fahrenheit and takes several hours to come up to temperature and several more to cool down. You can only imagine the electric bills when that thing is running.
