Electic Guitar Feed to Mixer

[Mustang1]

Hi everyone. I would appreciate help with a problem. Have started to mix sound for a six piece rock band. I pick up feed for the two lead/rhythm guitars by miking their Peavey VK212 combos but would like to explore picking up a direct feed, either before the amp input but after the effects pedal box
or alternatively after signal is amplified.
I appreciate I need to use a D.I box but not sure which one to use.
For example, which d.i box has a really good valve amp and speaker modelling facility to improve pure signal from guitar pickups?

Also, as the combo cabinets do not have a line out jack socket but only an output to additional speakers (over and above the 2 twelve inch spkrs fitted within cabinet) how do I take this hot feed and convert to mike level signal for input into mixer? (I have heard H and Kettner Classic Red Box is excellent for modelling but not sure it will handle a hot feed in from back of a combo without another speaker to feed out to.

Would be grateful for any advice re this area.
Thanks in advance.