Breaker must be double-ganged for 230V operation. Not two singles as you suggested. A 30 AMP should be sufficient for your application.

The breaker must also be compatible with your brand of breaker box (Murray, GE, etc) to insure fit and to insure you engage L1 and L2 in the box to obtain 230V.

Don't have my NEC book handy so can't comment on wire sizes.

As been suggested a sparkie (electrician)is your best friend here.

1998 Sportage - Gone.
2004 Honda Civic Coupe.
2007 Suzuki Grand Vitara - She got it.