played the demos of both - I know thats not always a great indicator - and they're both fine on keyboard/mouse, infact I probably wouldn't consider using a controller for either even though I have one.
Personally I'd go with Call Of Juarez but then I am a western FPS fan.
i played both and i own tomb raider as i got it for free with my 7900gt last year but i never really got into tomb raider and i downloaded the demo for call of juarez and found it very glitchy and very hard to play but the demo did come ot last year as well so i dont kno if its still buggy but i recomend tomb raider