A 10" or 12" mitre saw, depends on width of flooring to cut, & a stand is a much better option for cutting long lengths.
Are you flooring just one room, or a complete house, width of flooring.
With decking timber being Posts 100 x 100mm & Joists/ Beams 100 x 50mm or 150 x 50mm, you would need a 12" mitre saw to do all the decking.
A lot of outlay, for only one one or two jobs, better to hire a professional 12" sliding mitre saw one for a week or two.
A table saw is for ripping lengths of timber, you would find it hard cross cutting a long length of decking or flooring with one, easier to pull a saw across the wood.
EDIT: DeWalt DW713-GB 260mm - £215 crosscut 160mm
http://www.screwfix.com/p/dewalt-dw713-gb-1600w-250mm-compound-mitre-saw-240v/91683
A lot of the cheaper £200 saws are rubbish, some have free play, making accurate cutting impossible,better to stick with a well known brand.
A decent sliding mitre saw, you can add another £150 to the price, but you get a wider cut at 90 & 45 degrees, plus usually a 3 year warranty & a trade rated machine.
Best sliding mitre saw Bosch GCM 8 SJ £359:99p, will cross cut 270mm.
http://www.sitebox.ltd.uk/bosch-gcm...mm-dia-blade-obsch_gcm8sj?paid=googleproducts