IRA 101:
Traditional IRA uses pre-tax dollars going in and they get taxed when they come out.
Roth is the opposite. Uses already taxed dollars going in and they are untaxed coming out.
Since you pension is most likely untaxed at this point, it will go into a traditional IRA (rollover).
ps.. This is REALLY SUPER IMPORTANT.... Do NOT take possession of the fund yourself. Have the pension fund company transfer them directly to the broker you use. While technically, you have 59 days to take the funds yourself and put them in the new account, i can tell you horror stories of people who fucked this up. Do a direct rollover from one company to another and dont have the funds sent to you. Again, this sounds complicated but it super easy.