Sposoring Visitor visa to Parents and Uncle

[indian_in_uk]

Hi friends,

I am in HSMP visa in the UK and my visa is valid till Apr'2009. Me and my wife both are working here. My mom, aunt and uncle want to visit us in summer holidays (for one month). I thought of following documents that I will send across to them :

1) Letter to parents
2) Letter to High Comission
3) Copy of HSMP
4) Copy of passport
5) Salary slips
6) bank statements
7) council tax bill
8 ) utility bill
9) employer's letter

Do I have to send anything else?
Also, Can they apply for visa before their ticket is confirmed or they have to produce confirmed return ticket at embassy before applying for visa?

Please reply asap as I need to send documents today itself.

Thanks and regards