Controversial opinon here, but to be honest a SIPP is only really suitable where you intend to use the SIPP investment powers- e.g. purchasing a commercial property, individual shares. If your funds are going to be invested in mutual funds only then a good personal pension, or a pension on a "wrap" platform will suffice and should be a bit cheaper. Most of these offer a drawdown faciltiy. You would need to see an IFA about wraps as they are generally not available direct.
As for conslodating your pensions, you will need to if you do use drawdown, especially the smaller ones. It also make things easy from an income tracking and admin perspective. I would almost always recommend consolidating pensions before retirement.
Hope that helps a bit more.