Got myself into a pickle! What to do?

I made the mistake of looking at the poor bettas in the tiny jars at Petco, and fell in love with a cornflower blue with black face male. He's far from the most splendid betta in the world. He's also small (they all were). His body, less fins, is not much more than 1.5." He reminded me of the blue betta I had many years ago, that was much more attractive, with much longer fins, but still. . . . he was friendly, and came up to the side of the jar when he saw me, and followed my finger. They had Deltas, Halfmoon (already all sold) Crowntails, and this little Veiltail I just mentioned. They had at least 30 (most of them were red( but I can't get this little guy off my mind now.

I have a weird question. I have no tank, plants or supplies of any kind yet. There was a Aquedon 10 gallon for $49, included filter, but no heater. My question is; Can I buy him and keep him in a container with stress coat, and do daily water changes until I can get my new tank cycled? Or is there a high possibility of him dying in that time? Would he have a chance with a heater in the small tank? (It would probably be a Critter Keeper--I know, I know, but at least it would have a lid). Otherwise, if you guys think its a bad idea, I'll just have to wait until I get a tank and get it cycled. He would only be in the holding tank until his new tank was cycled.

I am afraid my heart over rules my head in these cases. I often bring a betta home without thinking it out! Most of my bettas are rescues(in that they were torn or tattered) and I think they would rather be in a critter keeper being looked after than dying in the pet shop. But that is me!

Heat is an important factor too. You can keep him in any container, but I recommend at least a minimum of a gallon for a temp setup.

Update for you guys. I put him in a one gallon cube thing because that's all they had at the LFS. Set up the 10 gallon, but couldn't keep him warm in the one gallon (our house is COOL at night to save on propane) so I just put him in the 10 gallon. So I'm cycling it with him in it. So far, so good. Master kit says PH is 7.6, Ammonia is .25ppm, Nitrites are zero, and Nitrates are 5.0ppm. The water is a little cloudy today, and hasn't been prior to this. I wonder why. I just tested the water today. Is this a normal part of cycling?

Did you put gravel in and how well did you rinse it? That could be whats causing some of the cloudiness.

Yes, I put gravel in. The girl at the LFS also gave me a small amount of gravel from one of their cycled tanks (and a small amount of their water). No, I didn't rinse the gravel! Didn't think about it. The cloudiness is now gone. Just went away on its own.

Since I last posted, I got two ghost shrimp, 2 albino corys and 2 mystery snails. The ammonia and nitrites are staying at the same level, and I've been testing it every day. Everyone is accounted for and doing well except for the smallest ghost shrimp. He has not showed himself at all today, and I suspect the betta ate him. Oh well, these things happen, I guess. I think the bigger one is too big for him to eat. I wish I'd only gotten 1 mystery snail. I didn't realize you can keep just one with no problem. I knew I needed more than one cory.

Haven't done a water change yet, but as soon as the ammonia starts going up, I will. I've had the tank set up for 3 days, and so far, no casualties (except for the shrimp). The betta is SO active and curious. He checks out the corys and bugs the snails. He flares at his leaf hammock too! What a character. I have the tank right around 79F and everyone is active. The snails are not really what I expected. I don't see them too often, and they don't crawl around much at all. Is this normal for mysteries?