At 150 is probably best to go for brain symb, go with syndicate brain if you can get help on the quest. The treatment should be easy but it should be the last thing that goes in as u will need a treatment head imp in for the rest of the twinking
As for the rest, it's very easy to get ql200 imps on at 150, too easy in fact. It may be possible to go higher but the stat reqs rise drastically after 200. Need to compare the bonuses from the best imps and the best symbs you can get in. I suspect that imps might still be the way to go and Sel is right, specialise as if you were going to create a pvp twink. Almost every pvp twink puts in a symb brain, apart from pre 25 characters and pre 120 docs. Try twinking a lvl 60 doc and you'll see what I mean, no viable brains
Definitely feet imp, evade close, dodge ranged and AAD.
As for rest, it depends which attribute you are going to be twinking on, I assume it's an opi fixer in which case it's probably going to be agil, though you could also do sense. Most twinks go by agil, but certain builds are better with others, 1hb enf trox = stam.
If you go really deep into it then you can twink different imps by different attributes but this is a very long term project and is probably overboard for S10.
Bugger armour, GA4 is still the best thing you can get on at 150. That combined with evade imps and your characters IP raised evades should give around 3k to defensive skills.
A question, which way are you leaning to for weapons?
Just spotted the weapon you'd be using, STILL the best weapon at that level and has the advantage of cutting out the need to implant MR.
M1