I think it really depends on the makeup of your team and your team needs. If possible, I try to get a couple "consistent" numbers guys along with at least one "homerun" guy.
My original thought was that Housh would be a more "consistent" scorer with Evans getting you weekly numbers, but with more explosive potential. Then I looked at the game data.
Housh Weekly scores, PPR, 1 point per 10 yards rush/rec
INJURED
INJURED
30 - 9 rec - 94 yards - 2 TD
13 - 4 rec - 95 yards
BYE
26 - 10 rec - 102 yards - TD
19 - 7 rec - 61 yards - TD
13 - 6 rec - 70 yards
15 - 3 rec - 66 yards - TD
15 - 7 rec - 88 yards
3 - 2 rec - 15 yards
20 - 7 rec - 79 yards - TD
26 - 10 rec - 106 yards - TD
25 - 8 rec - 118 yards - TD
8 - 4 rec - 49 yards
24 - 9 rec - 94 yards - TD
8 - 4 rec - 44 yards
8.5 targets per game
Housh actually had the 2nd highest ppg in my league's scoring system.
Evans Weekly scores, PPR, 1 point per 10 yards rush/rec
4 - 2 rec-19 yards
3 - 2 rec. 19 yards
18 - 8 rec -107 yards
16 - 7 rec - 90 yards
24 - 9 rec - 94 yards - TD
16 - 8 rec - 82 yards
2 - 1 rec - 11 yards
BYE
13 - 2 rec - 58 yards - TD
12 - 5 rec - 70 yards
49 - 11 rec - 265 yards - 2 TD
10 - 5 rec - 58 yards
9 - 5 rec - 45 yards
17 - 2 rec - 91 yards - TD
15 - 3 rec - 67 yards - TD
17 - 5 rec - 64 yards - TD
27 - 7 rec - 145 yards - TD
8.8 targets per game
I think Evans with a more seasoned Losman has a much, much higher ceiling than Housh just because of the lack of competition in BUF and his big-play potential. Either would be a quality addition to any roster.
Evans, aside from 3 real clunkers was actually very consistent and was on a serious hot streak to finish the season. I like guys who finish the season strong to do well the following season. Over the season Losman and Evans grew together, so I expect Evans to perform in similar fashion next season.
That being said, with his late-season flurry I can see Evans being slightly over-valued going into drafts next season and Housh slightly undervalued if people don't look at his numbers closely and assume that CJ will take most of his looks. A potential detractor for Housh mind you is Chris Henry. If he keeps his nose clean and isn't suspended throughout the season, he could eat into some of Housh's numbers.