Please, for your own sake, don't buy that strainer. It's barely worth the cost of the corrugated cardboard packaging it is shipped in. I had one on a Catalina and it was one of the first things to go!!
As for bronze barb fittings Jamestown Distributors, Hamilton Marine or Defender all stock them..
You want a real bronze, easy to clean strainer like this one made by Perko. It will hold LOTS of grass and sea weed before it reduces flow!!
It's sort of a pay now or pay later sort of thing.
Here are some ideas:
#1 You want the least amount elbows on your way to the strainer as possible.
#2 You want to use the biggest hose on the way to the strainer as possible. If your thru hull is a 1" full flow use 1" hose. If it's a 3/4" valve use 3/4" hose. I recommend a min of 1" intake hose to the strainer so that WHEN, not if, you need to snake it to clear it of weeds you can actually get a snake through it... I have converted every boat I have ever owned to a 1" intake system from the seacock to strainers intake port.
#3 You want to use either bronze or Marelon for all fittings bellow the waterline!! No nylon or PVC!!!!
#4 You want to use wire reinforced marine hose to keep the dia of the hose constant even with a radius bend.
P.S. Never mind you're on a rather sea weed free lake... I'll leave the info for others.. the advice about that strainer still stands though...
Oh and do something about those solid copper fuel lines
before your forking over big green to the EPA..!!!!!!