Mr Firman said the comprehensive start-up support from FXW Commercial Finance, which is run by a team with more than 200 years combined senior banking experience, had been invaluable.
FXW director Simon Harrison said: "Mr Firman has a track record of achievement in waste management and he is now making his specialist skills available to industry operators.
FXW director Paul Crane said: "If you look at the respective competencies, customer satisfaction and achievements of both FXW and Millfield, then the fit is obvious.
Like FXW, Millfield is independent so we are not tied to any particular financial products or institutions.
FXW, with offices in Swansea and Newport, is run by a team with more than 200 years combined banking experience.
FXW director Paul Crane said: "In his 10 years maintaining Cardiff Backpackers as the number one hostel in Wales, Sion has proved he knows what the market wants and can deliver.
To fund the acquisition and alterations, Mr Llewelyn turned to FXW Commercial Finance, run by a team of former senior corporate bankers, who helped secure the best deal from Barclays.
MONEY MEN: New appointments at FXW
, from left, Steve Symes, Keith Thomas and Martin Leech, with FXW
director Simon Harrison
did it all for me - quite frankly I did not have the time to get involved.
FXW, formerly Finance Exchange Wales, was founded five years ago by directors Paul Crane and Simon Harrison, whose long careers at senior levels with Barclays Bank have given them an in-depth knowledge of the finance industry.
FXW currently employs nine, with further recruitment in the pipeline.
FXW also has a sister company, FXW Financial Planning, headed by career banker Mike Evans, which deals with private finance, including residential and buy-to-let mortgages.