Firstly the Sahara SE will date from around 1994 or 1995 so you are probably best asking questions about it in the pre 1998 section rather than post 1998.
This is the one off eBay I assume?
http://cgi.ebay.co.uk/Saracen-Sahara-El ... _500wt_950
So it did come with wheels then...?
Anyway, it will be a well built frame and perhaps just one or two of the main tubes will be butted to save a little weight and add a bit of compliance. It will be a bit on the heavy side though.
The Saracen frames of that period ride nicely and last forever.
I'd certainly recommend replacing the forks with rigid ones, especially for touring. P2's are a good option assuming they don't have too long an axle to crown measurement, ie corrected for 100mm + suspension forks.
If the AtoC measurement is 390mm or less then the P2's should be fine. Any longer and the front end of the bike will be too high and your steering angles will be very slack.
Personally I prefer curved blade forks for touring as they have a bit a give to them. Comfort is everything on long tours.
Exage hubs can last for a very long time if they a serviced every year or so. They aren't as well sealed as the Shimano hubs further up the ranges so they are more susceptible to water and dirt ingress. But if you strip them down and re-grease them annually, and replace the bearings every couple of years or so, then they will pretty much last forever.
I've a few pairs of wheels with Exage hubs and they work just fine.
The Bontrager rims are not eyeletted so they aren't as strong as those with eyelets. That said, if the rim braking surfaces are in good condition and they are true and with evenly tensioned spokes, then they should give you no problems either.
I also have a set of wheels with those rims.
It'd be nice to see some photos now you've got it.
A real bargain by the way.