It has been done on earlier model SF and SG foresters but not sure I have ever seen that style of bar on an SH. You could do it for sure. There is going to a lot of fabrication involved. If you pay someone to do it I wouldn't be surprised if the whole lot ie. materials, fittings, fabrication and painting ended up costing more than a subaxtreme bar. However if you have the time, skills and equipment you could make something yourself for a few hundred dollars.
Take your front bumper off one day, crack a beer and sit down for a think. You will be surprised how much equipment is hidden behind there. You will need to find a new home for all of it or just delete some pieces. Washer bottles, horns, fog lights, air temperature sensor, helmholtz resonator for the air intake, headlight washers, impact bar, etc. Then consider how you are going to integrate the lines of your pipework into your body panels so it looks good. Take a piece of tape and try to make a single straight and horizontal line from your quarter panel under the grill back around the other quarter panel. This is where you are going to have to cut your front bumper. A laser level is very handy for this task.
If done well it could look very tough. If not done well it will attract the wrong type of attention. Even if done well, it certainly won't have ADR compliance so your airbag and crumple zones may not work properly which may have insurance consequences (I have customised front bar too so that doesn't bother me).
Consider too that if made from steel it is going to be strong but heavy (~20-30kg) which is ok on a Land cruiser but not necessarily desirable hanging on the front of a forester.
I say go for it, it will be hard work and take longer than you expected but in the end it's nice to have a unique car that you modified yourself.
