Reddit mentions of KYB 341072 Excel-G Gas Strut

I wouldn't replace the springs, they're probably fine.

Those rear struts are hard to find, only place I found them in stock is https://www.bernardiparts.com/Honda-SHOCK-ABSORBER-UNIT-R-RR-SHOWA__52611-SF1-904.aspx ...and I know nothing about that website so proceed with caution. Amazon.com has them listed for Prime but they're OOS at the moment; https://www.amazon.com/Genuine-Honda-52611-SF1-904-Shock-Absorber/dp/B00KTLYBDC If Rockauto has the rear struts I would just get those, and install them using the existing springs but make sure to purchase new strut mount kits for each side. I'd go with these: http://www.rockauto.com/en/partsearch/?partnum=52611SF1904
And ideally you'll want to replace anything rubber, so 2x mount kits and 2x insulator's if you're only doing the rear.

As for the front struts, Amazon has KYB's that will fit:
https://www.amazon.com/KYB-341073-Excel-G-Gas-Strut/dp/B000C3ZCQC/ref=sr_1_1?s=automotive&ie=UTF8&qid=1517847617&sr=1-1&keywords=kyb+341073&dpID=31HweufCZBL&preST=_SX300_QL70_&dpSrc=srch
https://www.amazon.com/KYB-341072-Excel-G-Gas-Strut/dp/B000C40S4C/ref=pd_sbs_263_1?_encoding=UTF8&pd_rd_i=B000C40S4C&pd_rd_r=8NFS0755RT4T9XETXVG2&pd_rd_w=PeQyY&pd_rd_wg=5l8KS&psc=1&refRID=8NFS0755RT4T9XETXVG2 Or get the Monroe equivalent: http://www.monroe.com/en-US/e-catalog/71829

However, I'm wondering if the sound you're hearing is the infamous "shock knock", but I've only heard of that happening to BB6's. Long story short it's the collar sleeve on the rear struts being 2mm too long and hitting the top washer. But again, I have no idea if this applies to non-5th gen's. It's a metal tapping sound that can occur with even the smallest bump, and I'm talking TINY bumps. Usually worse at low speeds when driving in parking lots or neighborhoods. If you're only hearing sounds intermittently when going over noticeable bumps then "shock knock" is probably not your issue.

Shock knock info here: http://www.superhonda.com/forum/f146/shock-knock-fixed-248073/
http://www.preludeonline.com/f89/write-up-5th-gen-shock-knock-fix-tsb-00-090-a-13702/

2 months ago I just replaced all the struts on my BB6 base, here is what I purchased to give you an idea of what parts are involved:

1x https://www.kyb.com/wp-content/themes/kyb_americas/partnumber.php?part=341178&position=Front%20Left&mfrlabel=Excel-G&parttype=Suspension%20Strut

1x https://www.kyb.com/wp-content/themes/kyb_americas/partnumber.php?part=341177&position=Front%20Right&mfrlabel=Excel-G&parttype=Suspension%20Strut

2x https://www.kyb.com/wp-content/themes/kyb_americas/partnumber.php?part=341179&position=Rear&mfrlabel=Excel-G&parttype=Suspension%20Strut

2x https://www.kyb.com/wp-content/themes/kyb_americas/partnumber.php?part=SM5058&position=Front&mfrlabel=Mount%20Components&parttype=Suspension%20Strut%20Mount%20Kit

2x https://www.kyb.com/wp-content/themes/kyb_americas/partnumber.php?part=SM5059&position=Rear&mfrlabel=Mount%20Components&parttype=Suspension%20Strut%20Mount%20Kit

2x https://www.kyb.com/wp-content/themes/kyb_americas/partnumber.php?part=SM5486&position=Front%20Upper&mfrlabel=Mount%20Components&parttype=Coil%20Spring%20Insulator

2x https://www.kyb.com/wp-content/themes/kyb_americas/partnumber.php?part=SM5360&position=Rear%20Upper&mfrlabel=Mount%20Components&parttype=Coil%20Spring%20Insulator

4x https://www.kyb.com/wp-content/themes/kyb_americas/partnumber.php?part=SB108&position=Front&mfrlabel=Strut%20Boots&parttype=Suspension%20Strut%20Bellows

PM me if you have any questions on the parts, I did quite a bit of research and educated myself on everything suspension related.
Good luck!