It all depends on what you want to accomplish. Any hardwood mulch will break down (compost) quicker than any bark mulch. The bigger coarser pine bark mulches last the longest.

If your bushes are mature (full sized and blooming) then you don't need to do anything special - just add some compost or mulch every year to help keep the area moist and provide a little nutrients to the root zone. If you just planted them and they are still filling out then you need to mulch more, feed more, water more.

They even have fake mulch, made of old rubber tires or whatever (I wouldn't use it in my yard but some people love it). The idea is to have a barrier around the bushes that helps keep things moist but inhibits weeds. If you want to replace it every year with fresh stuff then I'd go with hardwood - any hardwood mulch. If you want to replace it every couple of years then I would go with some of the pine bark fines or triple shredded pine bark or pine straw. If you want to replace it after like 5 years then I would go with the bigger chunks of pine or redwood bark.

If you want to match what was being used then I would scoop a handful up and take it with me to the store and see which type looks the closest.

Don�t ever buy mulch from Lowes or any other store, unless you have no other option. The reason I say this has nothing to do with the mulch, it is all price. You can go to landscape yard or mulch company and fill the back of your truck full for $20. Even with the cheap stuff from the store you can not make a dent for that price. I am sure that you can find one close to you and even if you don�t have a truck, I am sure the cost savings would still be huge if you had them deliver it.

What ncfg said. I can get an overflowing med sized pick up bed full of mulch for ten dollars.
I do have a pick up and I spread a dozen plus loads each year.
Even if I didn't have a pick up, I could get the same mulch delivered for forty which will still be way cheaper than anything in a bag.

you won't know the difference between double hammered and single hammered, other than the price of double being higher.