Amazon.com has quite a few collet chucks and accessories at its online store in the tools section. Most of the items on offer are for smaller applications. If anything here catches your interest, just click the links for more information:

Bosch 2610906283 1/4 Bosch 2610906283 1/4" Collet Chuck for 1613-,1617-, 1618- & 1619- Series Routers
List Price: $21.36
Sale Price: $11.72

Specifications: Part Number: 2610906283, Used on Model No. : 1617, 1617EVS, 1618, 1618EVS, 1613, 1613EVS, 1613AEVS, 1619EVS, Sales Pack Quantity: 1, Engineering Number: 2610906283.

Dremel 4486 MultiPro Keyless Chuck Dremel 4486 MultiPro Keyless Chuck
List Price: $12.13
Sale Price: $2.39

Bosch 2610906284 1/2 Bosch 2610906284 1/2" Collet Chuck for 1613-,1617-, 1618- & 1619- Series Routers
List Price: $21.36
Sale Price: $14.17

Specifications: Part Number: 2610906284, Used on Model No. : 1617, 1617EVS, 1618, 1618EVS, 1613, 1613EVS, 1613AEVS, 1619EVS, Sales Pack Quantity: 1, Engineering Number: 2610906284.

Bosch 2610906287 3/8 Bosch 2610906287 3/8" Collet Chuck for 1613-,1617-, 1618- & 1619- Series Routers
List Price: $21.36
Sale Price: $9.99

Specifications: Part Number: 2610906287, Used on Model No. : 1617, 1617EVS, 1618, 1618EVS, 1613, 1613EVS, 1613AEVS, 1619EVS.

Anytime Tools 1/4 Anytime Tools 1/4" MINI Snap In Hex Shank KEYLESS COLLET DRILL CHUCK
List Price: $15.00
Sale Price: $7.99

Special Chuck Fits Cordless Screwdrivers for Slow Speed Drilling. Also works as an adapter for your oversized drill chuck, quickly converting it for precise drilling with micro size bits. Features: Drop forged steel 1/4" easy snap-in hex shank Easily locks onto and releases drill bits Allows hex drive power tools to use conventional drill bits

Dremel 481 3/32 Dremel 481 3/32" Chuck Collet
List Price: $2.77
Sale Price: $1.50

Dremel 3/32" Collets Provides the optimal grip for bits offered for the Dremel rotary tool line and Heavy-Duty Flex-Shaft Tool (This collet is not suitable for the #236 handpiece)

PSI CXC/4 Expanding Collet Lathe Chuck Fits 1-by-8 tpi Spindles PSI CXC/4 Expanding Collet Lathe Chuck Fits 1-by-8 tpi Spindles
List Price: $40.15
Sale Price: $23.68

Hitachi 323421 1/2 Hitachi 323421 1/2" Collet Chuck For Hitachi Routers
List Price: $9.74
Sale Price: $8.60

Fits M12VC and many others

Dremel 483 1/32 Dremel 483 1/32" Chuck Collet
List Price: $2.77
Sale Price: $1.31

Dremel1/32" Collets Provides the optimal grip for bits offered for the Dremel rotary tool line and Heavy-Duty Flex-Shaft Tool (This collet is not suitable for the #236 handpiece)

Dremel 4485 Quick Change Collet Nut Kit Dremel 4485 Quick Change Collet Nut Kit
List Price: $7.20
Sale Price: $4.00

Dremel Quick Change Collet Nut Kit Allows you to quickly change collets to accept bits with shanks of 1/32" to 1/8". Includes 1 Each #480, #481, #482 and #483