Patience is a virtue, Mothernature. Typing takes time.
It does depend on what they've asked for, that is VERY important... anyway:
scrap 'take this opp.' Go direct:
I am writing to apply for...
Before 'I feel' I'd insert some background 'hook phrase' about the post that shows you have thought about it.
scrap 'extension to my abilities' - Go for 'challenge' or sommit like that.
I've worked for & - put in any concrete measurable achievements: Did you boost profit / cut expenses / got nominated for best employee / secured xyz changes / etc. - something they can't argue with.
I'd simplify the phrase describing your working timetable. Emphasise your flexibility in travelling to different offices if relevant.
'.... endeavoured....' phrase - I'd turn it around: I feel I would be an ideal candidate for this role because... [insert more / different qualities / skills / attendance / stuff from the 'achievement' text above you didn't use.
(latter has two 'l's)
'I have an advantage' is incorrect phrase here. 'confine' sounds a bit threatening to them: 'do it or I walk'... I'd turn it round into a positive conclusion:
I am looking forward to the challenge of xyz / expanding my knowledge of xyz / etc.
HTH