Even if the flue collars were trimmed down, it would be virtually impossible to attach the flexible aluminum liners.
The surround is only intended to cover any remaining space between the insert and the surround.
Is your current fireplace a manufactured box or masonry?
Will the large Innsbrook fit within my dimensions with the gas connection and blower?
Also,i am not sure if the surround and which base to order to cover the 4 3/4 lift up from the hearth?
This 6 inch perimeter surround will allow you to use the Empire Surround Bottom Cover - For SC336BL and S336BL Surrounds.
The cover is designed to match up with the bottom of the surround and will give the unit a finished look.
I want flat black, no frills, direct vent (both intake and exhaust) - least expensive.
I want the largest insert for the fireplace dimensions, with the smallest surround that will cover any gaps between the insert and the mantle.
I need a natural gas fireplace insert that is 34" wide, 24.5" tall and 24" deep (these are max dimensions).
There is tile on the mantle, so I'll probably need an insert surround.
On this Innsbrook direct vent insert (or all your gas fireplace inserts), they require a venting kit (to round or square clay flue pipe). This vent kit is indeed available, and you can find it here: Empire DVVK3FV Innsbrook Direct Vent Gas Fireplace Vertical Vent Kit - 25 Foot This venting kit is not included in the price for the Innsbrook insert.