We've used Pentair/Rainbow ProVac heads for years of our service vans. They do a great job, roll easily and steer well due to the swivel handle. Parts are readily available so we get 5+ years of daily use of 10+ vacuums per day before they need to be replaced. For your pool the 14" head would be a good size (R201276). We tried the ProVac 2 and didn't like it as much.

It's worth noting it's designed for 1-1\2" vacuum hoses, so if you have an 1-1\4" hose you'd have to remove the hose swivel and it won't work as well.

Short of the ProVac, I'd just get a cheap concrete pool vac and plan on replacing every couple years. I'd steer clear of liner vacs as they are a pain to vacuum with and have no benefit in your pool.