Just by looking at the photo it is impossible to tell if you will have fitting problems.
What will give you fits is if they cause you to fail the visual test come Smog Test time.
Trying to make ill-fitting exhaust parts fit is a problem if you don't have the equipment to bend,heat and tweak the parts. Suggest you find a friendly muffler shop to involve in the fitting. Here in Los Angeles that usually means going to the 'wrong' part of town and paying cash for the work.
If you think these parts will make a significant increase in power, you haven't done your homework.The power/torque benefit is usually small ,if any. The clear advantage if you use these parts to delete the precat (yes, the first one after the header,not the main cat)is to reduce the heat in the engine bay. That is a great benefit ,particularly for Bank 2(cyls.4,5,6). The problem is CEL. You may be able to evade that problem with 'extenders' and other hacks. But if you get a visual check at Smog ,you'll have to re-fit the old parts, may get tagged as a Gross Polluter. So get some savy local advice on all these issues. Coincidentaly I am considering doing exactly this to help reduce the heat under Bank 2.I have not yet found a good technical discussion of the issue. Mostly the mod was made for appearance or duboius power claims. It is a common mod on some other engines where the pre-cat disintegrates after about 5 years and plugs up the main cat.Now that is a serious issue to address.Pre cats do very little to reduce smog and are not used in many ROW countries so pollution is not a major valid objection to what you are considering. For those who are concerned about the pollution issue ,please do the researh before you flame me.It is the main cat and the O2 sensors that do the work. Precats used to be refered to as 'warm-up' cats.On older vehicles they often do more harm than good.If you do get new headers,consider ceramic coating them .It is a good time to do it.
I hope this helps.