Line speed estimates have already been covered. Basically you will get the same speed from every supplier, unless they are on that slows it down for extra stability. TalkTalk themselves for instance, and Sky slightly, though the TalkTalk one can be speeded up to the norm for other ISPs.
I think you will find Xilo still resell TalkTalk Wholesale and have added Be rather than replace TT. Ask them

. Pro 16 that you had before is still there, but doesn't show the £17.99 price.
If they don't do a monthly contract on it then
vivaciti do, without needing the line to be LLU as well, but to make it unlimited, which I think you would need, gets very expensive.
Vivaciti also have
an unlimited package based on C & W LLU.
Unfortunately I don't have ping data for any of these.
I don't know what the Xilo contract is on resold Be, but the top two on
this vivaciti page are Be, with free connection etc. at the moment. The Lite should do for you, as I think the only difference between the two is the downstream speed, and your line won't get near the limit of Lite.
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