Electronicaly signed rentagreement submitted for visitorvisa

[niki86]

I am planning to apply visitor visa for brother(Indian citizen) working in Dubai on work visa.
He plans to stay in UK for around 15-20 days for his holidays and will then go to India and then join back work in Dubai.

I have got electronically signed rent agreement(with initials of landlord and tenants) for my 1 bed property .
Is that ok to submit as part of visitor visa application or hand signed agreement is must?
I am also planning to submit my council tax (Band C) and utility bills like electricity or water for proof of accomodation for my brother.

Also if anyone can please guide me on the documents required by sponsor in uk and for the visitor (my brother ) in this case to apply for general visitor visa.