Kolsch Vs Alt Low Temp Fermentation

Hi all, I have been doing some research to brew an Abita Turbodog clone. The recipe from BYO recommends a lower fermentation temp with an irish ale yeast at 55-58 degrees f. I read a previous thread on the forums here with the recipe posted and one of the posts recommended using a Kolsch yeast, and another poster stated that Abita actually uses an Alt Yeast.

I have a few questions about this. From what I understand, the Kolsch has a little better attenuation than the alt, as well as the alt not accentuating hop flavors as much. What kind of attenuation can I expect with each in the 55-58 degree range? Also, any recommendations from anybody on which strain would get me the closest to the abita?

Also, the AG option in the recipe only recommends 7.5 lbs of pale malt, and according to the calculations from beersmith, this will put me at about 1.050 for SG. I also read another recipe for the clone that upped the pale malt to 9 lbs, which raises the SG to about 1.058. This may be a little high using a normal ale strain, but if I use the alt yeast, I can expect about a 1.016 FG, putting me at right around 5.5% abv, which is about right on with the Abita.
I may have just answered my question about the grain bill, but if anybody has any input on that, it would also be appreciated. Thanks for taking the time to read this.

I've brewed AHS's tubodog kit twice, once extract with english ale yeast (i accidentally mixed up the english and irish ale yeasts between that and an oatmeal stout) and once partial mash with WLP029, which is white labs kolsch yeast.

I'll also say that the extract batch was my first ever batch of beer, so factor that in however you like.

I much preferred the results of brewing with the kolsch yeast. Cleaner flavors, more chocolate came through in the after taste. I also fermented it at a cooler temp, around 66 vs 70 or so with the first batch.

Abita used to say on their labels that they use an alt yeast, although they've since changed their labels and i don't think they make any reference to the yeast anymore. If you read the description of WLP029, alt is one of the styles they recommend it for.

Thanks for the info. I'm leaning towards the kolsch, due to the better attenuation as well as it seeming like the hops will come through a little better.