Welcome Phil,
I was keeping an eye on that one on eBay, just out of curiosity!
No prior knowledge of the beastie, but the specification appeared to be good and it hasn't been bored out to the maximum oversize that sometimes can cause the piston to 'pick up' on the rear left of the bore. Make sure that you change the oil and filter after 2,000 miles, if used intermittently or 4,000 if you are using it regularly. Warm the engine through before giving it a bit of throttle.
I assume that you are aware of the ritual for starting a single? Do not snap the kickstart lever, they are like hens teeth and expensive if offered for sale. Make sure that the auto- valve lifter is properly adjusted.
DO NOT LUG THE ENGINE IN 5TH GEAR! What I mean by that is ensure that you are travelling at at least 50mph - 55mph before engaging 5th gear. It is a known weak point of the engine and if the gears start to break up or spall, hardened metal goes through the motor! Complete engine strip from top to bottom is needed. The oil pump takes a battering if this happens and whilst they are still available they are not cheap.
Use the 'Search' window in the top right of the board window on the 'Bike Problems' board, with the words 'SRX oil pump'. This will give you a good view of the various maladies that can afflict the machine!
If you need a workshop manual or other info, check the 'SEARCH' first and if nothing obvious appears, ask a question on the 'Bike Problems' board, we will try to help.
Do not let this put you off these machines as they are a very capable bit of kit that can fairly canter on. Enjoy it when it arrives!
Good health, Bill