Up your budget and get a TM VSR or you'll be disappointed. Sniping isn't cheap if you want it skirmishable - buy an AEG maybe if your budget can't reach. £120 will get you a pretty decent entry-level one. If those really aren't an option then maybe a JG BAR (which is a VSR clone) and then upgrade it over time. Again though, expect it to total around £350-400 when all is said and done.