The short answer is probably not. The shuttle tiles were produced by Lockheed in Sunnyvale. Ca, later with tweaks developed at NASA Ames. (Ref 1) /Revised data, see comment below/ The white shuttle tiles had a thermal conductivity at room temperature in air of 0.0485 w/(m K). (Refs 2 & 7) Currently, several vendors make insulating ceramics, including Cotronics' Rescor 310M machinable ceramic, Foundry Services' Fused Silica Foam-50, and Zircar Ceramics' UNIFORM C1. Although all of these have maximum service temperatures greater than 1000 C, their thermal conductivities are greater than shuttle tile by 3.86X, 2.89X, and 2.27X respectively. (Refs 3, 4, and 5) Since the conductivities are given at different temperatures and conditions, the comparisons listed are only approximate.
As far as I know, the only option for thermal insulation that surpasses shuttle tiles would be a silica aerogel. A typical silica aerogel at atmospheric pressure has a thermal conductivity of 0.017 w/(m K). (Ref 6) However, if you lower the pressure to a roughing pump vacuum (< 50 torr), the conductivity is reduced to 0.008 w/(m K). (The lower pressure increases the mean free path of the air so it is large compared to the size of the pores in the aerogel). The only downside, as I know from personal experience, is silica aerogels are very fragile.
Ref 1: Shuttle tile made by Lockheed
Ref 2: Shuttle tile data -
Ref 3: Cotronics' Rescor 310M
Ref 4: Foundry Services Fused Silica Foam-50
Ref 5: Zircar Ceramics' UNIFORM C1
Ref 6: Silica aerogel
Ref 7: Shuttle tile data