Peter
take care moving might cost you some seo juice.
Have you thought about slimming down to three sites adwords, local, seo and go for a more usefull url? i use
http://www.cleaning-carpet.co.uk/then sub domain
http://chelmsford.cleaning-carpet.co.uk/The reason for three is google will remove an seo place if you use adwords, not sure about local so by having different urls you avoid this.
Ip's are something else to think about
by building a mega site you have one site with loads of longtails and benefit from this. do worry about dupe content if you want same for each town. my adwords site lists well in some areas just by default.
You will save yourself money and time that can be diverted from marketing to selling and thats where you make more money.
Respects