Best one in my opinion is PhpBB, folowed by IPB or vBulletin (Paid) - hosting shouldn't be more than $4 or $5 a month with a free domain thrown in. You'd need not more than 1gb or so of space and one SQL database, with bandwidth entirely depending on your user base. Beyond that it's up to you - I recommend looking at reviews and comparison sites and choosing your best price to speed balance. Setup is easy for anyone with above-average competence, drop me a PM if you need a hand with anything. Free hosts are in my opinion unreliable, filled with adverts, and slow, with downtime and just about utterly useless.
DON'T under any circumstances use Servage - it looks good at first, with tons of space, cheapish hosting, free domain, but i have had nothing but trouble and they won't even release the domain I bought back to me. "Support" is non-existent, they have nowhere near the 99.9% uptime they advertise, upload speed is ridiculously slow, it has numerous misspellings and glitches in their management system, reeking of unprofessionalism, their cluster system is insecure and they take all the money up front with a tiny "cash-back" period of a week or so. the only way they stay afloat must be by publishing fake reviews and outright lying. STAY AWAY! (Personal experience)