2 runs of KK 8TC or 1 8TC and 1 4TC

I have original Silverline Sonatinas, Bryston B100, and Sim Audio .5 cd player. Will the Kimber Kables be overkill for my simple set-up? Any and most suggestions / advice welcome. I am currently using Morrow SP4 bi-wire.
They'll definitely sound different, but only you can judge if they're better. But if you plan to do a double biwire, I would definitely use the exact same cable for both runs, and not mix them.
I had the same speakers with a Pass Labs Aleph 3 amp. I used Zu Audio LIBTEC speaker cables, single run with Zu Ibis jumpers and they sounded great. If your budget allows, I would go with the ZU Event speaker cables, single run with jumpers, I have never heard a worthwhile improvement by bi-wireing.
I don't know which configuration would be better, or to use 12TC and jumpers. I wanted to post a response just to say that I have found the Hyper Pure copper used in the TC cables to be grain free. I use it throughout my system. I think it's a great bargain.

The 12TC has slightly better extension - I'd say a slightly fuller sound, but the 8TC on one of my systems works fine.

If it were me I'd just do the 12TC I think.

As for jumpers, I make my own using two pieces of Kimber TCX wire (same Hyper Pure copper) and Kimber Postmasters.

How long a run do you need for you speaker cables, by the way?
thanks for the info. I need 2 meters long
I'd suggest Kimber 16TC, which is basically a 12TC with a 4TC pulled through it.

Its available form Kimber at special request, I use it in my several of my demo systems and at Shows.

It can be configured as a single run or as a biwire with the 12TC part of it for the Low Frequency and the 4TC for the High Frequency at the speaker end, but with both tied together at the amplifier end, very clean solution. Contact me if interested in knowing more.

Good Listening