Need a expert for Wordpress PREMIUMPRESS auction theme!

I'm looking for HTML5, CSS3, PHP, MYSQL, JAVASCRIPT, JQUERY, AJAX, CodeIgniter, Wordpress expert!

Someone who've experience with PREMIUMPRESS auction theme/code have a + in my choice.

I would like to start with:

1: Add 0%, 6% or 21% VAT on (new) product (must be selected by subscriber/seller) and show on front-end.

2: Add house commission levels based on selling price (or on categorie? Cars, trucks, ...)
For example:
0€ -> 5000€ (+ VAT) = incl (or add) 7% commission + VAT
5001€ -> 15000€ (+ VAT) incl (or add) 5% commission + VAT
15001€ -> .... (+ VAT) incl (or add) 3% commission + VAT

3: Show commission and VAT amount + final price on frontend

4: Make layout with logo for existing php invoice (between seller and buyer and add VAT + commission fields)
- Make layout with logo for existing php invoice (commission to seller and add VAT field)

5: Name of highest bidder not fully anounced
(Nick Joly -> Nic******)
- Number of total bids on product page

...

I would like to work with one trusted developer for all my customisations now and in the future..

The codes for this theme is open source, I have allready codes with tweaks from github for this theme, that maybe can be used or tweaked but I leave it to the expert.

I prefer to work safe and step by step, 1 code at the time!
I'll pay also for 1 code each time, no milestones etc...

I know some codes are just 10min of work.

Please start your submission with: I know Premiumpress auction theme (so I know you read this post)

Thanks!