Wide field imaging lens

[JemC]

I have recently acquired a Vixen Polarie with the intension of doing some wide field imaging, 

I will be using my modified Canon 600D with it, Currently the only lens i have are a standard kit Canon 18-55mm and a old carl Zeiss Jenna 50mm , so i am looking at purchasing alternative lens to use,

The ones i am looking at for now are the following,

Canon EF 135mm f/2 L USM
 Canon EF 200mm f/2.8 L II USM
 Samyang 135mm f2 ED UMC
 Samyang 14mm Ultra Wide-Angle f/2.8 IF ED UMC 
 Sigma 150mm f/2.8 APO EX DG HSM Macro
 Tokina 11-16mm f/2.8 AT-X Pro DX

So my question is, has anyone used any of these ( other than the Samyang 135mm f2 ) for wide field and if so how did you find them, would you recommend any of them?

from the ones listed (other than the Samyang 135mm f2 ) would you say there are better ones to look at or any other i should consider?

Regards

James