Documents for Absence for an ILR @PEO

[sanjeev211161]

Hi
Is it true that that sometimes you do not get the confirmation of an ILR (Tier 1 General)the same day at a PEO? I have come to know this fact from word of mouth especially when a PEO at Glasgow do not have an expertise to handle straight cases. For example my earnings consists of two components one from a permanent job of a lecturer and the other from a casual short term job done before I took this permanent job. Further I have been out of country four times totaling 177 days in one of the 12 months period because of some personal reasons during my qualifying period of 5 years for ILR.
I would appreciate to know :
Can I apply to any PEO or contact them before applying?
Will I need any documents to support my absence for 177 days although it is less than 180 days?
Regards
Sanjeev