UCAS Personal Statement if Applying for a Year in Youth Volunteering?

Hi,

I'm currently in the process of applying to work at a youth retreat centre next year (after y13). My brother has worked at the same place and I'm pretty certain I'll get a place on the team (~12 selected normally and few applicants).

So, this poses the question: do I apply with this in mind (i.e. write about it on my personal statement) or just apply as normal (as if I'm not deferring, until I know for definite I have a place) and defer on results day? I'm told this is more frowned upon by universities to do but I don't want to write about a position I might not even have on my personal statement

Thanks