Researching chips and sourcing components
There are four basic criteria that a chip must meet to be selected for a design:


Functional Specifications
Physical Specifications
Low Cost
Good Availability


You can use the parametric search at the various distributors like Digikey and Mouser to find parts that meet all of these criteria.  Individual manufacturers also usually have parametric search functions at their websites, but the distributors allow you to compare between different manufacturers.  After a while, you start to learn which manufacturers have the most competitive parts in various categories.  The distributor parametric searches also allow you to limit the search to specific manufacturers, only parts that are in stock, sort by selected parameters, specific packages, etc.  It makes part selection much easier.

For a regulator search for example, you would first get to the regulator portion of the distributor's site and the specify ranges for voltages and current to see a selection of devices that meet your specs.

For parts with easily searchable characteristics, you can also often just google parametric requirements like 10A Buck Regulator and find promising parts.

Just like distributors allow you to search across manufacturers, once you have decided on a particular part, you can use findchips.com to search for the best price and availability across all of the distributors.  When you are actually purchasing parts, findchips.com saves a HUGE amount of time.

As for the specific case of the part that you are looking for, high current boost (voltage increase) converters are harder to find than high current buck (voltage decrease) converters.  In terms of power density, it's hard to beat Linear Technology µModule Regulators.  

Keep in mind that even with a 90% efficient supply you are looking at dissipating 5W (10% of 10A * 5V) in a very small space.  I hope that the tube is metal and you can thermally connect the regulator to it, or that the regulator doesn't have to run continuously.