SDS plus should fit this fine, its SDS MAX that is the "big boys" stuff.
But
quite frankly a £22 quick SDS drill? stick a "0" on that and its more like
it. I bought mine for about £180 in a deal at Jewsons, you can pay less or
a
lot more depending on what you want and how much use it will get.

For a a 1 metre deep hole you prob. need to look at SDS max so I'd ring
Hewdon or HSS first before buying anything. A SDS Max with a 1m core drill
could cost many, many hundreds to buy.

It won't be a meter long (Well I hope not!!

The stuff I am drilling seems to be pretty soft
My Bosh cordless 12v hammer drill went in 400mm like butter!

I think it is sandstone, but am not too sure

Sparks...