Best bet to satisfy the design dilemma is to do a google image search, something along the lines of "handheld shower with clawfoot tub". You can add "vintage" or "Victorian" or whatever style you may be leaning towards. The search should bring up photos or ideas and you can sort out what you two do and don't like.

If you can't find Title 20 compliant hardware online, when you find something you like call up the manufacturer and ask them if they have a compliant version. They usually have a compliant version to stay competitive, often times it's simply a matter of that item not making it into the sellers inventory. It can usually be shipped directly from the manufacturer.

Here's a link to Axor, the fancy end of Hansgrohe. I used this Montreux model in one of my baths, though there was not a shower. They have a wall control for the shower, but I don't know if they still make the wall bar with the sliding head. I'm sure they used to, but they may have trimmed the line down, and are using more generic looking shower head and bar.

ETA, as I watched the little video on the Montreux line, I can see they still have the Montreux shower bar and head. The little details are all there. Very nice look I think

http://www.hansgrohe-usa.com/18873.htm

Heres my bath:

And my sink; I've got the cross handles instead of the lever handles shown in the clip on their web page:

I have the same dilemma, and it's getting stricter. By the time I'm ready to remodel my third bathroom next year, California Title 20 will restrict shower heads to 1.8 GPM (starting 1 July 2018). This past summer, the maximum flow rate on lavatory faucets was reduced from 1.5 to 1.2 GPM to meet Cal Green requirements.

There's a small local company called "High Sierra Showerheads," which has developed low-flow showers. Any reviews?

When I remodeled two bathrooms in 2015, I used the Hansgrohe Raindance shower heads, which will no longer meet Cal water conservation efforts.

There are no "plumbing police" patrolling the area, but If I sell my home, I will need to disclose that the shower heads and faucets I installed in 2015 are non-compliant, but the frustrating, inefficient, low-flush Toto toilets can stay.

So, I'm searching for compliant products (faucets and shower heads) for the third bathroom remodel:

There's the Hansgrohe Croma Select E shower head, at 1.8 GPM.

The Kohler Purist shower head has a 1.75 GPM, but the Purist faucets flow at 1.5 GPM. Kohler has some new faucet lines, such as Composed, which meet the 1.2 GPM max, with matching shower trims but no shower heads.

Dornbracht has new faucet lines, CL.1 and Lisee, which meet the 1.2 GPM restriction, but their shower heads are at 2.0 GPM.

"California Faucets" sells shower heads with replaceable filters to meet the shower restrictions.

I'm open to suggestions...

plan2remodel, did you ever find a solution? We are in remodeling now, and have same issue but after reading your post and seeing the 1.2gpm limit I think i now have 2 issues (sigh). I did not know CA faucets had different filters but do know they are pricey (but may be only way). If you found anything I would be interested to hear. thanks

joenlizhouse, my remodeling plans for the hallway bathroom have been postponed to 2019. I have seen several options that will meet the latest Cal Green water flow restrictions. Dornbracht and Graff both have several lines that will work -- these tend to be modern style, which I prefer. Local store says Fantini's Venezia collection (pricey Italian faucets) can meet the restrictions, also, but that may be above my budget.