i also use the lrp sharks, i use the short wheel base for our medium sized track on a friday night and i use my shark long wheel base for the summer and winter series as the track is massive,
now for backup and parts i would suggest you get the losi mini 8ight which i dont own myself yet as i have too many shark spares to even consider it, but if you look for lrp shark parts on the web they are getting scarse lately although you can pick them up in the states under the name duratrax vendetta,
the losi mini 8ight, if you search for spares for that car, they are everywhere.
the losi sells new for £184.99, which is pretty good for a ready to race car.
you can get the sharks second hand for between £40 and £150, all depends what it comes with, and they still hold their own against the losi, the fastest drivers at our track still have sharks.
there is a good one on ebay at the moment, which i am watching but wont be bidding on as i have 5 complete cars and enough spares to build another 7 at least, lol,
http://www.ebay.co.uk/itm/LRP-Shark-...#ht_646wt_1185