I rewired my last house, but got a Sparky in to connect the meter tails to the new consumer unit and do the final test, commisioning and sign off.
This was before there was a requirement to as well, but I just wanted to be sure.
I did it as part of a complete restoration, so I could run all the sockets I wanted, where I wanted them, and run all the kitchen pelmet lights switched from the main room switch point etc
As someone else has said, run all your coax / stereo / speaker / Network cables at the same time, whether or not you use them now, you will be glad you did once its all plastered and decorated
I ran a 10mm2 sub main up into the loft direct from the Consumer unit too, then a Garage consumer unit up in the loft for a seperate lighting ring and power ring up there.
Also ran an "outside power" Ring from the RCD protected side of the board for all the garden stuff.
Have a think about what you want in the house and where, its easier to have sockets un used than to need more than you`ve put in.
Even if you do all the 1st fix, get all your boxes & cables in, get it tested.
Then you can do all the stripping of cables for connection...... youll save a lot of money but itll take you longer than a sparky I think.
HTH
Dom