Wow. If you got $1000 to hire assistants, you got more money for it that we do.
We've been fortunate to have some guys (usually dads) who are solid people and good coaches. Maybe we're just lucky.
But beyond finding someone, there are a couple housekeeping things you need to remember for your coaches. I would have whoever you decide to bring in as an assistant meet with your principal and go ahead and fill out the paperwork as if you were going to hire that person as a teacher. That means doing one of those pesky background checks. to be sure your coach isn't on things like the sex offenders list (don't laugh ... it happens).
Also, this reinforces the idea that this is a serious task, not something to be taken lightly. Afterall, a school and a bunch of parents are going to entrust their kids to you for several hours each week.
TAPPS requires any high school coach (varsity, subvarsity or assistant who is involved in instruction in a sport) to have produced proof of coaches education. Unless you've coached for five years at a high school (and provide proof of same), you'll need to take a couple courses from NFHS or equivalents ... I think one is a general coaching course, another a sport specific course, a third is an athletic first aid course (a general CPR course isn't the equivalent) and the fourth is a concussion management course. The first three might cost you $30-50 each; the fourth is free and each may take you a few hours of your time. You also have to view (on the website) something called the TAPPS SCOPE course, similiar to the UIL COPE course. It's boring, but grab a pizza and you can knock it out in a night.
Again, all that sounds like a hassle, but it makes anyone who wants to coach realize the true committment behind the job and can help run off those daddies who think that they're the greatest coaching genius since Vince Lombardi and are happy to stand on your sidelines on game day only and impart their obvious greater football wisdom to you and your kids ... regardless of what you taught all those days in practice. Oh, and they'll help keep the officials in line, too. Always a big help, right? (PS ... Have your school administrators help you out. They can put a rule in the school rules that limit coaching to those approved by the school administration and that have demonstrated their "qualifications" through education, etc. Then they can weed out the troublesome daddies who want to spend their time on your sideline.)
Although it's getting late to do this, I'd try to get my coaches together and attend a Clinic somewhere as a group (although this could be a shameless plug, since I run a Clinic every year). Not a bad way for everybody to spend a day or two and make it a kind of mini-retreat and start planning the upcoming season.
If your team is fortunate to make state, TAPPS will check to be sure all those folks on the sideline coaching have completed their coaching registration requirements. And woe be to those who didn't.