Although I am the same as you in the bionic department now that I am starting to dabbling with the fancier stuff in the game.
I feel some calling to a Chimera mutation, where the mutation takes the wheel, really good and bad traits,but eating to rapidly regen with all the extra attack mutations seems neat
Afaik, every mutated part that can attack rolls its own attack roll, so something like hooves, claws, clubbed tail, fangs and horns roll independently and can lead to crazy attack dps
Alpha seems to be the most vanilla plus mutation but I personally have difficulty finding the recipes to make the respectable mutagens - remember reading taking Alpha Post-threshold and mixing it with trogolodyte for a good combo
Medical can be really useful for someone that likes to play riskier and melee as they have very high pain threshold and acid blood post threshold
Mouse is a dex-character build plus ( smaller and faster) and you can ride to battle on your mighty dog steed - preferably tamed before mutation
Spider is a really nice tactical mutation as you can eventually spin webs for slows, z-level traversal and using it for fire traps and can also combo bleeding damage with poison from fangs
Elf-A is the "pretty" mutation, makes npc interaction easier, can have some nasty side effects namely weak and radioactive potential problems, but can commune with trees and needs very little sleep when post threshold