Quarter horses are no more 'low-key' (not high strung) than draft horses are gentle giants. You can find A LOT of qh's with spunk!
But you get the horse YOU want. Just because everyone else has qh', tb's or what have you doesn't mean you gotta get that breed! I went with a draft, way different than from what everyone else around here has.
A good horse can cost you anywhere from $200 to $200,000. Just depends on the horse and what you want to pay. No matter what the price, ALWAYS get a vet check.
Boarding can be done in different ways. Full care which they pay for everything, stall cleaning, turn out, feed; partial care, they do some of the cleaning, some of the feeding; self care, you take care of the horse; pasture only - no stall.
I do full care for $300 a month. That includes: all the hay, grain, cleaning six days a week (boarders clean on Sundays), turn out, tack storage, wash rack etc.
Shots twice a year: $65 and $35
Teeth floating: $135 to $250 (once a year)
Trip call: $50 each visit
Emergency care: a lot of money especially vet calls after hours
I pay $100 every 6 weeks, but I have a draft. Most farriers are $55 to $75 for shoes and a little less for just trims on light horses
Tack you need
Couple of pads
Possibly breast collar
Get more than one halter
A few cotton leadropes
I haven't seen any horse that can't do englsh AND western so don't let that limit you.
Unless it weighs a ton... it's just a horse. Draft horse motto.