Currently, extra feet and hand parts can be bought for MSD, SD and SD13 boy all in pureskin. All three skintones are available in each part, however, sunlight and snow skin are currently available only at Tenshi No Sato in Kyoto.

"Old Skin" optional parts have been discontinued (info on old parts below...)

IMPORTANT: Currently NO optional heads, torsos, legs or arms, etc. are available. Only feet and hands. The only exception to this is the heads referred to as the 'painting school' or 'painting class' heads. For more about Painting School Heads, please see this page.

Old DISCONTINUED OPTIONAL PARTS : (all parts below are discontinued. You can still find some of them in Volks stores, but only until they sell out. After that, they are not making more of them)

None of the following parts work with SD13 boys or MSD.

There are four different types of bodies that can be bought, three of them jointed. B-01 is the standard SD girl body. B-02 is the standard jointed body. B-03 and B-04 both have larger breasts; B-04 has the same size waist as B-02, and B-03 has a thinner waist. B-03 is called the 'western' body, because it is designed to suit western style clothes better, with the more curved figure that is favoured in the west. B-02 and B-04 are called 'Japanese' bodies, because they are designed to suit traditional Japanese style clothes better, fitting with the body style more favoured in Japan.

B-01 = 14,800 yen
B-02 through B-04 = 19,800 yen

There are three types of legs available. L-01 is the standard SD girl leg. L-02 is called 'long' and is 25mm longer than L-01. L-03 is called 'slender' and is 5mm thinner than L-01.
All legs cost 12,800 yen (for a pair).

There are three types of arms available. A-01 is the standard SD girl arm. A-02 is called 'long' and is 10mm longer than A-01. A-03 is called 'slender' and is 5mm thinner than A-01.
All arms cost 7,800 yen (for a pair).

There are eight types of hands available. (Not all shown in picture.) Additional photos: H-01, H-03, H-06, H-07, H-08, H-09
All hands cost 3,800 yen (for a pair).

There are five types of feet available. F-01 is the standard SD girl foot. F-02 is the foot that SD Nono comes with; it is chubbier than the standard foot. F-03 is the high-heeled foot. (Please note that this is different from the SD13 girl high-heeled foot.) F-04 (unsure). F-05 is the split-toed foot, specifically designed for wearing Japanese style 'geta' shoes.
All feet cost 3,800 yen (for a pair).

There are also 12 optional heads available. (Please see more below.)
can I buy any head I want as an optional part?

There are 12 heads that Volks sells separately as optional parts. These heads are number F-04 through to F-15. A picture can be see here. The F-09 head is the same head as the limited edition dolls Licht and Leona, and the F-13 head is the same head as the standard girl Mimi. The F-05 head is the same face as the standard four sisters head (Kira, Sara, Nana and Megu), except that it has closed eyes.

All Optional Heads cost 12,800 yen.

These are the only heads that Volks sells separately as optional parts. The heads of any of the other standard release SDs can only be bought by either buying the whole doll, or by buying a Full Choice System doll. Additionally, there are three heads that are only available when buying a Full Choice System doll. (F-27, F-28, and F-29.)

Most limited edition dolls have unique heads that cannot be bought in any other way except for buying that doll. While the FCS F-28 is similar to the Lucas/Chris head, and the FCS F-29 is similar to the Cecile head, they are not the same, and most other limited edition dolls have headmolds that are very different from any other available doll.

There is also a head that is referred to as the 'painting school' or 'painting class' head. For more about Painting School Heads, please see this page. (These heads are NOT discontinued...)

If you are after a difficult to find head, your most likely option is Yahoo! Japan Auctions, but keep in mind that limited edition heads can go for quite a large sum of money, particularly if they are painted by popular customizers.