Oh yeah you asked about the rail trail as well

Here is the web link to info about it

http://www.centralotagorailtrail.co.nz/

My BF and I have done it twice and had a great time both times. The first time we just did the trail itself (from Middlemarch to Clyde) the second time we went the other direction and detoured off to go to Naseby (which has some great mountain biking but the forest was closed due to fire risk when we were there in the height of a very dry summer) and St Bathans. We took three days over it the first time and four days the second time.

Its nice, entirely traffic free riding. The surface is dirt and gravel. We used mountain bikes. I've seen people do it on touring bikes but I think that would be tough. The scenery is really very spectacular in places. If you avoid the summer school holidays it is very uncrowded (both times we have done it in late January we have seen less than ten (and maybe as few as five) other groups of riders. Accomodation is adequate but not spectacular (in some places there is only camping and very basic pub or backpacker style accomodation).