Personally I would just do the work if you are confident, then get your mate's, mate to inspect it to make sure its up to scratch, I wouldn't expect him to put his name to the work in some form of completion certificate however.
Lets be honest here, you are not required to have any kind of electrical certificate done in order to sell your house, currently, and even if the building regs stazi were to come and look at your installation they would have a hard job proving that you installed it.
Just do your reasearch, use some common sense and at least get someone who does know to double check what your have done. The fact you are wanting to use IP related gear suggests over engineering as opposed to going out to B&Q and buying a roll of speaker wire and using a couple of 1960's bakelite sockets you bought at the local car boot sale.
Lets be honest here, you are not required to have any kind of electrical certificate done in order to sell your house, currently, and even if the building regs stazi were to come and look at your installation they would have a hard job proving that you installed it.
Just do your reasearch, use some common sense and at least get someone who does know to double check what your have done. The fact you are wanting to use IP related gear suggests over engineering as opposed to going out to B&Q and buying a roll of speaker wire and using a couple of 1960's bakelite sockets you bought at the local car boot sale.