Harbor Freight carries one, if you can't find it on their web page you will need to call and ask. It isn't too expensive either.
I use the same gun. I spray epoxy and 2K with the regular 1.4 tip. It works fairly decent. You have to put a few more coats of 2K when you use this gun but it still builds nice. I actually used a cheap $14 conventional gun to spray the first two thick coats of 2K on the car. Then I blocked and blocked and blocked. Between each block coat, I used the 43430 gun to apply a slightly thinner layer of 2K to give me a new starting point to find any highs and lows. This worked very well for me.
Also the 43430 gun with 1.4 tip sprays the SPI epoxy nice. This gun is a nice unit for primer, single stage, and base coat paints but I don't like it one bit for clear coat. I just can't get it to atomize the paint nice and still keep a nice pattern. Thus I'm currently looking for a higher end gun to spray base and clear. I'm considering the devilbiss gfg-670 plus or the iwata lph400. I'll still use the 43430 gun for all primer and other odds and ends though.